Emulsion containing a plant extract, method for producing said emulsion and for obtaining a plant extract

ABSTRACT

The relates to a method for obtaining triterpenes from plants and/or the constituents thereof, in addition to an emulsion whose aqueous and fatty phase is emulsified by the plant extract. The plant extract contains at least one triterpene and/or a triterpene derivative and the emulsion contains at least one oil and/or fat and water. The invention further relates to a method for production of said emulsion and to the use of said triterpenes in the production of cosmetics and medicaments.

[0001] The present invention concerns a process for obtaining triterpenes and/or their components as well as an emulsion, of which the aqueous and fatty phases are emulsified by a plant extract, wherein the plant extract contains at least one triterpene and/or a triterpene divertive and the emulsion further contains at least one oil and/or fat and water. Besides this, the present invention concerns a process for producing the emulsion as well as the use of the triterpenes for production of cosmetics and pharmaceuticals.

[0002] Natural ingredients, fragrances or flavors and active substances have for a long time been isolated, using various extraction techniques, from whole plants and their parts, such as leaves, roots, fruits or bark. As one of the first natural substances, betulin (birch camphor), the substance which imparts to birch bark its white color, was extracted from plant material in the year 1788 (Lowitz, M., Chemische Analysen, Hrsg. Crell, L., Vol. 2, page 312). Subsequent to this first isolation there followed scientific studies, including elementary analysis of betulin, which were published by U. Hausmann 1876 (Hausmann, U., Annalen der Chemis, 182, page 368).

[0003] Betulin containing plants are widely distributed in the plant kingdom. They belong primarily to the Hamamelididae (angiosperm plants), where in one single species in the order fagales (birch relatives), and more particularly in the family of the betulaceen (birches), the content of betulin accumulates in the outer bark (review article: Hayek, E. W. et al., (1989), A Bicentennial of Betulin, Phytochemistry, 28(9), pages 2229-2242). The white part of the birch bark, in particular the species betula pedula, betula verrucosa and betula papyfera can contain more than 30% betulin. More precise research was published by Rainer Ekman in the year 1983, according to which 21-40% triterpene, or 16.7-34% betulin, were extracted from the dry outer bark of betula verrucosa (Ekman, R. (1983a), Holzforschung, 37, page 205-211). The inner bark, in comparison, contained only traces of triterpenes, in the realm of approximately 0.37-0.43% (Eckman, R. (1983b), Finn. Chem. Letters, page 162).

[0004] Betulin is a pentacyclic triterpene with a lupan skeleton, which is also referred to as betulinol, trochoton, birch camphor and (coryli) resinol. The characterizing feature of the lupan group is a ring with five carbon atoms within the pentacyclic system, which contains an α-isopentyl group in the position C-19. Betulin is further characterized by a high thermal stability, its melting point lies between 250 and 260° C., wherein even high values are obtained after sublimation of the re-crystallized product. Its molecular weight is 442.7, it is soluble in pyridine and tetrahydrofuran, however only slightly soluble in dichloromethane, chloroform and cold organic solvents, wherein its solubility however significantly increases with increasing temperature. In water and cold petroleum ether [carbohydrate with 5 to 8 C-atoms (C₅-C₈ CH)] betulin is practically insoluble. Besides this, kinetic research has shown low reactivity of the hydroxy group of betulin (review article: Jääskeläinen, P. (1981), Paperi ja Puu—Papper och Trä 10, pages 599-603).

[0005] Already in the year 1899 J. Wheeler demonstrated the antiseptic characteristics of betulin, it is thus used for sterilization of bandages and adhesive medical plaster (Wheeler, J. 1899), Pharm. J., The Production of Betulin by Sublimation, 494, Ref. Chem. Centr. 1900 I, page 353). In natural medicine and folk remedies products from cooking birch bark were and are still employed, wherein however only the inner part is used, which contains only residue of the white birch bark and, due to its low solubility, most likely contains no betulin, since the content of betulin in the inner bark is less than 0.5% and betulin is insoluble in water or water-alcohol mixtures (up to 60% alcohol) (Ekman, R. (1983b), supra).

[0006] The thus obtained product of boiling is used for treatment of hot flashes, water craving, gout and for skin diseases, as well as a tincture for bandages for abscesses. Further, birch bark is used for production of birch bark oil, which has also been used for treatment of rheumatism and as aroma therapy (Hansel, R. et al., (Hrsg.), (1994), Drug A-D, Springer Publishing House, Chapter Betula, pages 502-511; Hyek, E. W. supra). Besides this, the use of birch extracts as bath salts for treatment, particularly for sweaty feet, as well as additives to shampoos as a hair care agent is known (Nowak, G. A., (1966), Cosmetic and Medicinal Properties of the Birch, Amer. Perfumer Cosmet., 81, page 37). Here, however, only aqueous extracts from birch leaves have been employed, which contain practically no betulin.

[0007] Newer research suggests a medicinal effect of betulin and betulin derivatives. In animal tests betulinic acid inhibited the replication of retroviruses, in particular the human immune deficiency virus (HIV1). The published bacteriostatic and bactericidal effect of betulin against intestinal Escherichia coli, Salmonella typhi, Shigella flexneri and Staphylococcus aureus suggest a broader medicinal application (Chen Sun, J. et. al., (1998), Anti-AIDS Agents, 32, Synthesis and anti-HIV activity of Betulin derivates, Bioorganic & Medical Chemistry Letters 8, pages. 1267-1272; Evers, M. et. al., (1996), Betulinic acid derivates: a new class of human immunodeficiency virus type 1 specific inhibitors with a new mode of action, J. Med. Chem. 39, pages 1056-1068; Hayek, E. W. et. al., supra). Further an anti-inflammatory, cortisone like effect as well as cytostatic effect upon use in vitro against various tumor cell lines of betulin and betulin derivatives has been shown (Carmen Recio, M., et. al. (1995), Investigations on the steroidal anti-inflammatory activity of triterpenoids from Diospyros leucomelas, Planta Med. 61, pages 9-12); Yasukawa, K., et. al., (1991), Sterol and triterpene derivates from plants ( . . . ), Oncogene 48, pages 72-76).

[0008] For obtaining betulin from birch bark, in particular from birch cork, one could consider using, besides sublimation (Lowitz, M., supra), above all extraction in broiling solvents. As solvent there are employed mainly alcohol and chlorinated carbohydrates (Ukkonen, K. and Era, V., (1979), Kemia-Kemi 5, pages 217-220; Ekman, R. (1983a), supra; Eckermann, C. and Ekman, R., (1985), Paperi ja Puu—Papper och Tra 3, pages 100-106; O'Connell, M. M. et al., (1988), Phytochemistry 7, pages 2175-2176; Hua, Y. et al., (1991), Journal of Wood Chemistry and Technology 11(4), pages 503-516).

[0009] The disadvantage of the sublimation technique is the fact that the content is obtained only with very low yield, which necessitates the use of large amounts of starting materials. Besides this, a particular disadvantage of the sublimation technique is the simultaneous occurrence of tar-like decomposition products from other cork/bark components, which necessitates multiple re-sublimation or re-crystallization. With the use of the extraction method it is particularly disadvantageous that betulin is relatively poorly soluble in the mentioned solvents and the extraction can only be carried out with high investment in time. Here also multiple re-crystallizations are necessary. The best results are obtained with higher boiling carbohydrates (Eckermann, C. and Ekman, R. (1985), supra). These are however particularly disadvantageous for use in cosmetics and medicines due to the unavoidable residual solvents in the product.

[0010] Solvents, in which betulin is highly soluble, such as for example pyridine and tetrohydrofuran, are generally considered to be toxins. They are dismissed on the basis of their health risk and their not insubstantial handling risks during extraction. A further disadvantage of the mentioned solvents is that substantial amounts of brown, undesired substances are dissolved at the same time, of which the later separation is extremely complex and costly and uneconomical. Accordingly, until today there is no efficient process for obtaining betulin from birch cork, whereby betulin can be produced in large amounts, with a high degree of purity and without using strong hazardous solvents.

[0011] In the state of the art, further processes are know for extraction of lipophilic natural substances using high pressure and high temperature. For example, in U.S. Pat. No. 5,843,311 a process is described for isolation of organic materials using organic solvents. With the aid of this analytic process, which is used on a small scale, samples can be tested for contaminants, impurities or additives. This analytic process is used primarily for monitoring in the nutrition and health agent industry, in the pharmaceutical industry and in the analysis of ground samples. A disadvantage of this process is its limitation to the small analytical scale.

[0012] In U.S. Pat. No. 5,647,976 a reaction vessel is described, which can be employed for extraction of contents with solvents with high pressure and elevated temperature. This reaction vessel is characterized by a lock, which makes it possible to introduce solvents in the reaction vessel and to remove them therefrom, without having to disturb the lock. In this manner contamination of the solvent is effectively prevented. In addition, the reaction vessel is simple to operate, so that it can be operated even by untrained personnel. U.S. Pat. No. 5,647,976 essentially describes the mentioned reaction vessel, however gives not direction as to how to carry out an extraction process. Besides this, it contains no indication regarding the quality and purity of the contents which have been isolated in the reaction vessel. U.S. Pat. No. 5,660,727 discloses the use of the reaction vessel from U.S. Pat. No. 5,647,976 in an automatic rotation unit, which enables the simultaneous analysis of multiple samples. The volume of each reaction vessel which can be introduced into the reaction unit lies between 10 and 30 ml. Thus, these devices find application in the analytic realm, and they are not suitable for employment in a large-scale framework.

[0013] In U.S. Pat. No. 5,785,856, which is a divisional of U.S. Pat. No. 5,660,727, there is described, besides the rotation device, also a process for extraction of components using solvents. The process is carried out under increased pressure and elevated temperature. For this, the reaction vessel is filled with the sample material to be analyzed, and the rotation unit is activated and automatically has solvent added to it. Subsequently the pressure and the temperature are increased to predetermined values. After successful extraction the solvent is diverted to a receptacle container. The reaction vessel inclusive of the supply and removal lines can be rinsed with an inert gas such as for example nitrogen for cleaning. A disadvantage of the process is in particular that it may be suitable for extracting soluble substances in an analytic sample, however is not or is only poorly suitable for preparative production and yielding of components in greater amounts and purity, since it is precisely in such processes that contamination of the sample leads to defects in the degree of purity of the extracted components. Further, the process as described in U.S. Pat. No. 5,785,856 as conceived is limited to the analytical realm. The document provides no indication regarding obtainable degrees of purity and the possibility for scaling up to industrial scale.

[0014] All processes described in the state of the art work discontinuously, that is, a predetermined amount is respectively extracted in a vessel to be filled and subsequently emptied. Until now no continuous process has been made available, for continuously supplying plant materials and fresh solvent, extracting in a counter-current process, and simultaneously withdrawing the extract-saturated solvent as well the completely extracted plant material.

[0015] Besides this, in the state of the art various attempts have already been undertaken to modify the surface or scalp active characteristics of betulin, in order to produce technically useful products. So, for example, Pasich already carried out experiments in the 60's with betulin and its esters such as the succianates, phthalates and tetrachlorophthalates as emulsifiers for white vaseline, whale oil and peanut oil, and came to the conclusion that betulin, with respect to its emulsification properties, that its, ability to connect aqueous and oily components with each other, was comparable with known technical or industrial emulsifiers. His betulin containing emulsifiers were however less stable. He employed re-crystallized betulin and achieved no satisfactory stability of the emulsions. Preferred were the phthalate and tetrachlorophthalate, which were produced with the objective of better water solubility. Oily layers separated out of the emulsions after a short time, which indicated its insufficient stability. Besides this, anti-microbial effective preservatives were added to the described emulsifiers, whereby primarily benzoic acid derivatives were employed (Pasich, J., 1965), Triterpenoid emulsifiers of plant origin. V. Emulsifying properties of Betulin and certain of its esters. Farm. Polska 21, Nr. 17-18, pages 661-666).

[0016] It is however precisely the addition of preservatives, which for their part can induce allergenic and toxic effects, which frequently destroy the positive therapeutic effect of the betulin, particularly on damaged skin, so that the preparations of betulin containing emulsions described in the literature cannot be used, or be used only to a limited extent, in modern skin care.

[0017] These disadvantages in the state of the art have resulted in no mentionable technical preparation, use or employment of the triterpenes contained in birch cork, in particular the betulin contained therein in large amounts, despite the large amounts of birch bark available today as waste product in wood harvesting.

[0018] The amounts of presently non-utilized betulin are enormous. Even considering only one single pulp factory in Finland (UPM Kymmene, Lappeenranta, Finland) an extractable amount of approximately 4,000 to 5,000 tons of betulin per year are incinerated as waste. In Sweden, Finland, Russia and Canada a large number of pulp factories of this size are operational. An economic utilization of this replenishable natural resource stands and falls with the economic feisability of the extraction process, which until now has not been described, and which is made available for the first time by the present invention.

[0019] The present invention has as a first objective the provision of a process which, with the use of tenable solvents, makes possible the obtaining of large amounts of triterpenes with high purity in either the batch process or a continuous process. Besides this, this process should provide the possibility of utilizing the birch bark that is presently a waste product in the pulp industry. Besides this, the process should be simple, cost effective and rapidly completed. Further, it should be guaranteed that the amount of residual solvent in the extract falls within the guidelines of the European pharmaceutical handbook, and in particular the “Guideline for Residual Solvents”: ICH Q3C-Impurities (ICH=International Conference on Harmonization of technical requirements for registration of pharmaceuticals for human use). The present invention further addresses the task of providing a triterpene containing emulsion which contains pharmaceutically active components and at the same time is sufficiently stable for a longer period of time without the addition of preservatives. Besides this, the emulsion should be capable of preparation in a simple manner.

[0020] The first task is solved thereby, that in the inventive process for obtaining of triterpenes from plants and/or their components the plant parts are first washed at 20° C. to 70° C. in a solvent in which the triterpenes are not soluble or only slightly soluble.

[0021] Subsequently the triterpenes are extracted with a solvent under increased pressure and elevated temperature. Next, there is carried out a cooling and simultaneous depressurization of the triterpene containing solution, whereby the triterpenes precipitate in the solvent in extremely small particles and then more triterpene crystallizes onto these particles upon further cooling. In order to further increase the purity of the triterpenes, they are washed following filtration at room temperature with a fresh solvent. By this process it is in particular achieved, that triterpenes can be obtained in simple manner on an industrial scale.

[0022] In the framework of the present invention the expression “washing ( . . . ) in a solvent, in which the triterpene ( . . . ) is not or is only slightly soluble” means that the solubility of the triterpene is not more than 1 g/liter. By this first washing step the easily soluble impurities are removed in advantageous manner.

[0023] The extraction of the triterpene occurs with solvent under increased pressure and elevated temperature, in certain cases in the supercritical region. Therein there can be used as solvents for example supercritical carbon dioxide as well as carbohydrates in the supercritical region as well as liquid carbohydrates under elevated pressure or mixtures of different carbohydrates.

[0024] Prior to washing [step (e)] it is advantageous that it is not necessary to dry the filter cake in a further process step. Thereby the process is particularly simple to carry out.

[0025] Besides this, the washing of the triterpene [step (e)] can itself be carried out under normal conditions, thereby keeping the inventive process particularly simple and economical.

[0026] In a particularly preferred embodiment the inventive process is carried out continuously. For this, the plat material and cold solvent are conveyed through a pressure-tight tube by pumping, and washed in a counter-current at 20° C. to 70° C. By a second pump system the washed plant material is conveyed in a second, likewise pressure-tight and heatable tube or pipe and extracted in counter-current with fresh, supercritical heated or liquid solvent. The discharge of the wash solution and the extraction solution occurs respectively via a filter system. The plant parts are conveyed counter-current to the solvent flow on the basis of their different density and are discharged at the end opposite to the solvent discharge end. The extract solution is—with maintenance of the pressure in the extraction system—conveyed to spray nozzles via a valve system and it is only here that it is finally reduced in pressure.

[0027] Birch bark is available in large amounts as an economical raw material in particular as waste products in the pulp industry. In a preferred embodiment of the present invention the triterpenes are obtained from birch bark, preferably from the white part of the birch bark, which is also referred to as birch cork.

[0028] “Separated birch cork” refers to both the white outer layer when stripped by hand, which is sloughed off outwardly as cork skin by the trunk of the birches and thus lies outside of the actual bark, as well as the subsequently separated birch cork separated for example with the aid of a hammer mill and a flotation process from a total skinning.

[0029] In a particularly preferred embodiment the triterpene is obtained in a purity of at least 80%, preferably 85%, in particular 90%, particularly preferably above 90%.

[0030] In a further illustrative embodiment the main component of the extracted triterpene is betulin, wherein its content is at least 80%, preferably 85%, in particular 90%, particularly preferably above 90%.

[0031] Further, it is advantageous to use the same solvent for the first washing step, the actual extraction and the subsequent washing step. In this manner the best purity values can be achieved. Beyond this, it is particularly simple to carry out the process when using only one single solvent.

[0032] As solvent there is particularly suitable a low boiling carbohydrate or a mixture which includes a low boiling carbohydrate, since a low boiling carbohydrate can be subsequently very easily removed. The boiling point of the employed carbohydrate, or as the case may be the mixture, preferably lies below 100° C. Particularly preferred is the employment of n-pentane, n-hexane or n-heptane, since all are inexpensive, do not harbor any special health hazards and are available in sufficient quantities in good quality.

[0033] It has been found to be of particular advantage to employ for the first washing step that solvent which was collected as filtrate after the main extraction. In this manner large amounts of impurities are removed from the starting material in advance, without having to expend any additional fresh solvent. These contaminations or impurities would have had a negative influence on the degree of purity following extraction. In order to further increase the degree of purity, the extracted components can be subsequently post washed with fresh solvent.

[0034] In a preferred embodiment the first washing step is carried under a pressure of 1 to 300 bar, preferably 10 to 35 bar, particularly preferably about 25 bar. The actual extraction occurs preferably at a temperature of 50 to 200° C., preferably 140 to 160° C., particularly preferably about 150° C. and under a pressure of 1 to 300 bar, preferably 10 to 35 bar, particularly preferably about 25 bar. In these extraction conditions large amounts of pure triterpenes, in particular pure betulin, are obtained.

[0035] The inventive process has also been found to be of particular advantage, when the crystallization of the triterpene occurs as micro-crystallization with an average particle size of <40 μm, in particular from 2 to 32 μm.

[0036] A further atribute of the present invention is an emulsion, of which the aqueous and fatty phases are emulsified by a plant extract, wherein the plant extract includes at least one triterpene and/or at least one derivative of a triterpene and the emulsion further includes at least one oil and/or fat and water.

[0037] The triterpene and/or its derivative preserves and emulsifies the emulsion. Besides this, it is pharmaceutically active. Thereby it is in particular achieved, that the emulsion contains no supplemental preservative, and thus possesses a particularly high degree of purity and a good compatibility above all with problematic applications to damaged skin.

[0038] The plant extract is herein an extract of birch bark, preferably from the white part of the birch bark, which is referred to as birch cork.

[0039] In a further embodiment the plant extract contains at least one of the substances betulin, betulinic acid, betulonic acid, lupeol (lupol), erythrodiol, allobetulin, phellonic acid, hydroxy-lactone, betulonic aldehyde, β-amyrin, oleanolic acid, ursolic acid, esterified betulin and/or β-sitosterol. These plant constituents could be employed individually as well as mixed with each other in various combinations in the inventive emulsion. A particularly suitable combination is comprised of betulin>80%, betulinic acid<10%, lupeol<3%, oleanolic acid<4%, erythrodiol<4% and water<1%.

[0040] The emulsion preferably contains the triterpene and/or its derivative in a concentration of 2 to 10%. Depending upon the desired consistency, the proportion of the triterpene and/or its derivative can be varied in the mentioned concentration range. For the employment of a fluid lotion the emulsion exhibits for example a concentration of the triterpene and/or its derivative of 2 to 3.5%. If the emulsion is used in the form of a cream, the concentration of the triterpene and/or its derivative is preferably 3.5 and 10%.

[0041] The oily and/or fatty component of the emulsion can be selected from any of the dermatological and cosmetic known oils and fats. Particularly suitable are animal and plant fats such as jojoba oil, peanut oil and olive oil. Particularly preferred is the use of avocado and/or almond oil.

[0042] In order to regulate the consistency of the inventive emulsion, conventional moisturizers and/or thickeners and solidifiers can be employed. As moisturizers there can be employed in particular glycerin and urea or carbamide. Herein above all concentrations of respectively 3 to 10% glycerin and/or urea or carbamide are suitable based upon the amount of the emulsion. As thickener there can be employed, for example, polysaccharides, which are to be added in a concentration of 0.2 to 2%, preferably 0.5%, based upon the amount of the employed water. Natural polysaccharides as well as further sugar compounds and their derivatives are particularly suitable, since they do not react with the other components of the emulsion, they do not modify them and are thus chemically inert.

[0043] Thus the polysaccharide agar agar is preferably employed. Agar agar is a mixture of agarouse and agaropectin, which is obtained from red algae and has the advantage that it cannot be decomposed by most micro-organisms. Alternatively, the polysaccharide carrageenan can be employed which occurs naturally in the cell wall of red algae and certain brown algae and has the same advantages as agar agar.

[0044] In a further embodiment the emulsion comprises 2 to 10% extract from the white part of the birch bark, 20 to 30% avocado oil, 10 to 20% almond oil and 40 to 68% water. The most preferred concentrations comprise 4% extract from the white part of the birch bark, 29.3% avocado oil, 14.7% almond oil and 52% water.

[0045] A further inventive emulsion contains 2 to 10% extract from the white part of the birch bark, 20 to 30% avocado oil, 10 to 20% almond oil, 5 to 10% moisturizing agent and 30 to 63% water. Herein the most preferred is the concentration of 4% extract from the white part of the birch bark, 29.3% avocado oil, 14.7% almond oil, 5% glycerin and/or 5% urea and 42 to 47% water.

[0046] The extract from the white part of the birch bark, which is contained in all emulsions, comprises at least 80% betulin, at most 10% betulinic acid, at most 3% lupeol and at most 4% oleanolic acid.

[0047] The emulsion, on the basis of its composition and its verifiable biocompatibility, is particularly suitable as a salve base for addition of all known fragrances, cosmetics and medicinal active agents.

[0048] A further atribute of the invention is a process for producing the inventive emulsion, wherein the process includes the following steps:

[0049] (a) dispersion of triterpene in an oil and/or fat;

[0050] (b) emulsification of water;

[0051] (c) homogenization of the emulsion to the desired consistency.

[0052] Herein the dispersion and homogenization preferably occurs in a homogenizing mixer since the process can be carried in particularly simple manner in this way. Further, it is possible to prepare small amounts of emulsion for individual applications.

[0053] In a particularly preferred embodiment there is added to the water which is used during emulsification a moisturizing agent, in particular glycerin and/or urea, or a thickener, in particular a polysaccharide. Thereby a particularly creamy consistency can be achieved.

[0054] A further attribute of the present invention is the use of the triterpenes for manufacture of a cosmetic, preferably in the form of a salve, a lotion, a cream, a gel, a jelly, a tincture, a shampoo, a powder and/or a cosmetic (compact) powder, in particular for application upon the skin, the face or scalp or scalp and/or for inhalation. On the basis of its chemical relationship to sterols the triterpenes, in particular the obtained betulin, are particularly suitable for skin and head care. It relaxes and smoothes skin, reduces the water loss and induces attractiveness and blush. Thereby the cosmetic can be particularly employed for maintaining moisture of the skin and smoothing the skin as well as for reduction of age spots and can be employed in the case of dandruff or flaking skin. A further advantage is the water insolubility of the triterpenes, so that skin which is exposed to water vigorously and for prolonged periods is particularly well protected. On the basis of the anti-bacterial effect the use as deodorant is particularly advantageous. Added to this is the minimization of transpiration on the basis of an effective closure of the sweat glands.

[0055] A further attribute of the present invention is the use of the triterpenes for production of a pharmaceutical or medicinal formulation, preferably in the form of a salve, a lotion, a cream, a gel, a jelly, a tincture, a shampoo, a powder and/or a cosmetic (compact) powder, in particular for application upon the skin, the face or scalp or scalp, and/or for inhalation, particularly preferably for treatment of dermatological conditions of the skin and/or the scalp, above all for neurodermitis, psoriasis, contact eczema, melanoderma, impetigo, pre-cancerous conditions of the skin as well as for inhalation during asthmatic attacks and/or for substitution in place of glucocorticoids. Likewise, on the basis of their high purity, the obtained triterpenes, in particular the obtained betulin, is suitable for the therapeutic application on pre-cancerous skin.

[0056] The inventive emulsion is so well suited for the above-mentioned applications because the extract from the white part of the birch bark includes no mutagenic characteristics. Topical toxicity tests were likewise carried out, wherefrom no sensitizing characteristics were discovered.

[0057] The following examples serve for illustrating and imparting a better understanding of the present invention, but should in no way be considered as limitations.

EXAMPLES I. Clinical Observations

[0058] Various clinic observations of dermatological skin changes were carried out by general practice doctors as well as clinical doctors. Following the diagnosis by the doctors there occurred a treatment of the patients with the inventive emulsion, which was produced in accordance with described processes.

Example 1

[0059] Patient: male, 68 years

[0060] Diagnosis: heavy, generalized psoriasis vulgaris

[0061] Pre-Treatment: medium strength cortisone salve

[0062] Application: scalp

[0063] Treatment: multiple daily application of the inventive emulsion as salve upon the afflicted skin areas

[0064] Results: the occurrence of psoriasis efflorescence following application of the cortisone salve was prevented by the application of the inventive emulsion

Example 2

[0065] Patient: male, 48 years

[0066] Diagnosis: light psoriasis vulgaris

[0067] Pre-Treatment: medium strength cortisone salve

[0068] Application: head

[0069] Treatment: multiple daily application of the inventive emulsion as salve upon the afflicted skin areas

[0070] Results: healing of the approximately dollar-piece sized presternal inflamed focal areas of the infection on the head upon application of the inventive emulsion within 14 days; reinflamation of the infection (=recidivist) after cessation of application of emulsion; renewed definite improvement upon resumption of the treatment

Example 3

[0071] Patient: female, 5 months

[0072] Diagnosis: neurodermitis, hyperkeratotic, prematurely aged, chapped-shriveled skin

[0073] Application: body

[0074] Treatment: multiple daily applications of the inventive emulsion as salve upon the afflicted skin areas

[0075] Results: very noticeable improvement, excellent effectiveness with simultaneously good compatibility

Example 4

[0076] Patient: female, 10 years

[0077] Diagnosis: neurodermitis, hyperkeratotic, prematurely aged, chapped-shriveled skin

[0078] Application: body

[0079] Treatment: multiple daily applications of the inventive emulsion as salve upon the afflicted skin areas

[0080] Results: very noticeable improvement, excellent effectiveness with simultaneously good compatibility

Example 5

[0081] Patient: male, 5 months

[0082] Diagnosis: neurodermitis, hyperkeratotic, prematurely aged, chapped-shriveled skin

[0083] Application: body

[0084] Treatment: multiple daily applications of the inventive emulsion as salve upon the afflicted skin areas

[0085] Results: very noticeable improvement, excellent effectiveness with simultaneously good compatibility.

Example 6

[0086] Patient: female, 28 years

[0087] Diagnosis: neurodermitis, neuodermitic effloresce

[0088] Application: elbows, face or scalp, neck line

[0089] Pre-Treatment: Dermatodoron, Stibium metallicum, salve, Top-isolon-bartel salve, mesembryanthemum salve, following application of these salves there resulted no overall improvement of the neurodermitic sites

[0090] Treatment: multiple daily application of the inventive emulsion as salve upon the afflicted skin areas

[0091] Results: significant reduction of the neurodermitis

Example 7

[0092] Patient: female, 78 years

[0093] Diagnosis: seborrheic eczema

[0094] Application: head

[0095] Treatment: multiple daily application of the inventive emulsion as salve upon the afflicted skin areas

[0096] Results: reduction of scab formation in the scalp area, red areas blistered somewhat slower

Example 8

[0097] Patient: female, 55 years

[0098] Diagnosis: strong itching, dandruff, moist eczema

[0099] Application: scalp, head

[0100] Treatment: multiple daily application of the inventive emulsion as salve upon the afflicted skin areas

[0101] Results: visible improvement of the treated areas

Example 9

[0102] Patient: female, 33 years

[0103] Diagnosis: dry, itching, easily infected scabbing eczema

[0104] Application: lower side

[0105] Treatment: multiple daily application of the inventive emulsion as salve upon the afflicted skin areas

[0106] Results: not yet evaluated

II. Production of the Plant Extract

[0107] Starting Material: Birch cork

[0108] A) Description of Quality Assurance

[0109] The birch cork was delivered by:

[0110] 1. The “wood pulp company Kaukas” (UPM-Kymmene Lappeenranta, Finland). Kaukas separates the bark mechanically from the birch wood and the cork is also mechanically removed from the inner bark.

[0111] 2. Co-workers, which cut the cork by hand.

[0112] In a first step the mechanically separated and the hand cut cork is analyzed regarding its identity. For this purpose the cork is microscopically examined, whereby multiple individual cork layers and lenticular cells, which are typical for birch, can be seen. In addition the extractable amount of triterpenes with n-hexane at 140 to 160° C. under increasing pressure is examined. The extractable amount of triterpene with the main component betulin exceeded 10%, since such amounts occur only in the cork of birches with white bark. For the monitoring of purity of the material, subsequently an analysis with respect to aflatoxins, heavy metals, herbicides and pesticides was carried out according to European standards.

[0113] B) Shredded Cork

[0114] The cork was ground in a cutting mill (produced by the company Retsch) and suctioned off out of the machine through a sieve with a pore size of 1 mm diameter. For the further extraction, only particles with a particle size ≦1 mm were employed.

[0115] Extraction of the Triterpene

[0116] For extraction, advantage was taken of the phenomenon that triterpene is practically insoluable from birch cork in cold n-hexane, is however is well soluable in hot n-hexane (140 to 160° C.) under pressure. This process was carried out in two steps:

[0117] 1. The cork was cleansed in a Soxhlett apparatus using a Soxhlett process with n-hexane (hot, <boiling point 69° C.) until the n-hexane solution was no longer yellow.

[0118] 2. The active component or ingredient was extracted from the pre-washed cork granulate with n-hexane at 140 to 160° C. under elevated pressure (extraction by means of Dionex ASE 300 with 100 ml vessels). Upon the quenching of the overheated solution containing n-hexane and triterpene a crystallization occurred immediately, so that a micro-crystalline powder of triterpene was obtained directly in the cold n-hexane. This powder was filtered and washed twice in cold n-hexane. The triterpene was dried at 80 to 100° C.

[0119] Determination of the Purity of the Extract

[0120] The purity of the extract was monitored using gas chromatography (GC). The result is represented in the following diagram.

[0121] Overview: GC of the Extract of Birch Cork with Cholesterol as Internal Standard

[0122] Determination: Active Substances in Salve Determination in Salve 018701

[0123] The following values were measured:

[0124] Betulin: at least 80%

[0125] Betulinic acid: at most 10%

[0126] Lupeol: at most 3%

[0127] Oleanolic acid: at most 4%

[0128] The overview shows a typical gas chromatogram with values of 84 to 86% betulin, 4 to 5% betulinic acid, approximately 1% lupeol and approximately 1% oleanolic acid.

[0129] According to the requirements of the ICH the amount of the solvent n-hexane remaining must be <7,725 mg/kg extract, while a cream containing 4% birch cork extract may not contain more than 290 mg/kg n-hexane. Typical values comprise 1,500 mg/kg n-hexane in dried extract, which corresponds to approximately 60 mg/kg in the birch cream.

[0130] Final Inspection

[0131] Each charge was checked according to the European requirements with respect to the acid value (<5) and the peroxide number (<15) by means of a standardized process. The content of birch cork extract was analyzed using GC. Further, an examination was made regarding microbes (<100/g); besides this, no pathological microbes may be contained.

III. Inventive Formulation (Birch Cream)

[0132] The inventive formulation is set forth in Table 1 (Tab. 1). They were comprised of the following composition: TAB. 1 Composition of the Formulation Active Component in all Extract from Birch cork Formulations 40 ± 4 mg/g Cream (4%) Formulation Ingredient in % Birch Cream A 29.3 Avocado oil 14.7 Almond oil 52 Water Birch Cream G 29.3 Avocado oil 14.7 Almond oil 5 Glycerin 47 Water Birch Cream H 29.3 Avocado oil 14.7 Almond oil 5 Urea 47 Water

[0133] All three formations contained the same amount of the active component (birch cork extract) as well as avocado and almond oil. They differed essentially with respect to the component urea (only in birch cream H) as well as glycerin (only in birch cream G), birch cream A is free of these components.

[0134] Stability Test

[0135] The birch cream was centrifuged at 500×g and was found to be stable therein.

IV. Toxicological Tests

[0136] 1. Acute Toxicity

[0137] The acute toxicity of the birch cork extract was determined by intra-peritoneal and subcutaneous administration to mice and rats.

[0138] Mice

[0139] Individual doses of birch cork extract (charge number: Bet. 001) in Methocel as carrier were subcutaneously administered to five male and five female CD-1 mice. The animals were treated with a dose of 2000 mg/kg based upon their body weight.

[0140] The lethality was determined 14 days after the administration of an individual dose for determination of the average lethal dose LD₅₀. At the same time the animals were observed in order to detect symptoms of toxicity. As such there were considered local and systemic intolerance reactions as well as changes in the body weight. The animals were sacrificed at the end of the experiment and examined microscopically. The acute toxicity test followed EC guidelines L 383 A: B1.

[0141] Under the given test conditions (2000 mg birch cork extract/kg body weight) no intolerance reactions were observed. The animals showed the expected weight gain during the experimental period. The results are assembled in Table 2 (Tab. 2). TAB. 2 Acute Toxicity in Mice Average body weight during the experimental period Average Body Weight (g) Male Female Beginning 22.8 19.8 Day 7 27.0 22.2 Day 14 31.2 23.6

[0142] In the macroscopic examination changes were observed in three males and three female animals, which could be traced back to the technical examination process employed.

[0143] In this toxicity test the area of the first intolerance reaction, the lowest lethal value as well as the LD₅₀ value lie above 2000 mg birch cork extract/kg body weight.

[0144] Upon intra-peritoneal administration of the birch cork extract in mice toxic symptoms were observed above 500 mg/kg body weight. Only light toxic reactions, such as reduced passive amount of movement, interference in movement coordination and reduced muscle stretch resistance were observed. From this it was concluded, that the toxic symptoms were to be traced back to stomach fur inflammation (peritonitis), which was brought about by the extract solution. A LD₅₀ value could not be determined, so that in the observed time period of 14 days this lie above 200 mg/kg body weight.

[0145] Rats

[0146] Individual doses of birch cork extract (charge number: Bet. 001) in Methocel as carrier were subcutaneously administered to five male and five female Sprague-Dawley rats. The animals were treated with a dose of 2000 mg/kg based upon their body weight.

[0147] The lethality and toxic symptoms were determined 14 days after the administration of an individual dose. The animals were sacrificed at the end of the experiment and examined microscopically. The acute toxicity test followed EC guidelines L 383 A: B1.

[0148] Under the given test conditions (2000 mg birch cork extract/kg body weight) no intolerance reactions or lethality were observed. The animals showed the expected weight gain during the experimental period.

[0149] In the macroscopic examination changes were observed in three males and three female animals, which could be traced back to the technical examination process employed. The results are assembled in Table 3 (Tab. 3). TAB. 3 Acute Toxicity in Rats Sprague-Dawley Rats (n = 5/sex) Birch cork extract 2000 mg/kg body weight Symptoms/Criteria Male Female Local intolerance reaction none none Systemic intolerance reaction small small Mortality within 6/24 hours none none in 7/14 days Average body weight (g) Beginning 187.6 174.4 Day 7 239.8 203.8 Day 14 280.8 218.0 Loss of body weight none none Macroscopic result 1/5 3/5

[0150] In this toxicity test the range of the first intolerance reaction, the lowest lethal value as well as the LD5₀ value lie above 2000 mg birch cork extract/kg body weight.

[0151] Upon intraperitoneal administration of the birch cork extract in rats toxic symptoms were observed above 500 mg/kg body weight. Only light toxic reactions, such as reduced passive amount of movement, interference in movement coordination and reduced muscle stretch resistance were observed. From this it was concluded, that the toxic symptoms were to be traced back to stomach fur inflammation (peritonitis), which was brought about by the extract solution. A LD₅₀ value could not be determined, so that in the observed time period of 14 days this lie above 200 mg/kg body weight.

[0152] Further Actions

[0153] The OECD guidelines establish that no further experimentation is necessary, when over a time span of 14 days with an administation of 2000 mg/kg body weight in mice and rats (for each five animals/sex) no mortality resulted from the tested product.

[0154] Chemicals are classified on the basis of their relative toxicity. They are characterized as toxic when the LD₅₀ valve us between 50 and 500 mg/kg body weight. With a LD₅₀ value of 5000 to 15000 mg/kg body weight there is the presumption of practically no toxicity.

[0155] In the present case it has been established that the LD₅₀ value is >2000 mg/kg body weight, and is very likely also >5000 mg/kg body weight, since even with the high value of 2000 mg/kg body weight no toxic symptoms were observed. As can be seen from the experimental results, the birch cork extract can be characterized as non-toxic.

[0156] 2. Subacute Toxicity

[0157] Rats, Intra-peritoneal (i.p.)

[0158] Birch cork extract (charge-number: Bet. 009) was administered to experimental rats (Sprague-Dawley/Crl: CD® BR) by means of intraperitoneal injection over 14 days within the framework of a subacute toxicity test. The test protocol is summarized in Table 4 (Tab. 4). TAB. 4 Test Protocol of a Subacute Toxicity Test (Rats, i.p.) Animals: 40: (20 male, 20 female) Sprague-Dawley Crl: CD ® BR rats Animal Groups: Group 1-5 5 male/5 female animals in each group Additional 4 (2 male, 2 female) reserve animals, as possible replacements during the acclimation phase Test Protocol*⁾: Birch cork extract (= component of birch cream) Batch number: Bet. 009 Carrier: sesame oil Dose Amount: Group 1: 20 ml carrier/kg body weight/day Group 2: 500 mg/kg body weight/day Group 3: 1000 mg/kg body weight/day Group 4: 2000 mg/kg body weight/day Administration Volume: 20 ml/kg body weight/day Number of Doses: 1 Administration Period: 14 days (day 1-14) Test Period: 15 days (day 1-15)

[0159] This subacute toxicity test was used for determining the dose, which was employed in a four week subchronic toxicity test. The results of the toxicity test are shown in Table 5 (Tab. 5). TAB. 5 Subacute Toxicity Tests in Rats 1 2 3 4 Mortality none none none N = 8¹⁾ Clinical Result: none in individual²⁾ in all animals greatly animals >Day 13 >Day 10 >Day 7 enlarged abdomen Raw fur none none in all animals >Day 10 >Day 7 Lose in body none in all male animals in both weight >week 1: sexes −18%*⁾ −14%*⁾ >Week 1: End of week 2: −15%*⁾ −15% −12% (male) −12% (female) Change in food none none none reduction intake in test week 1: male: −29% female: −31% Hemotological none none differences to the change (see see (Tab. 6) control group (see Tab. 6) Tab. 6) Changes in none Urea ASAT Urea ASAT Urea ASAT Clinical (see (see Tab. 6) LDH LDH and all Biochemistry Tab. 6) (see Tab. 6) further parameters in the female animals and almost all further parameters in the male animals

[0160] The changes in the clinical biochemistry (Tab. 5) are significant relative to the control only in groups 3 and 4 (p≦0.01); in Group 3 with respect to the ASAT activity (+113/+132%), in Group 4 only with female animals with respect to the parameters: total protein, urea in the blood, calcium, potassium and LDH activity. TAB. 6 Hematological changes in the subacute toxicity test (Rat, i.p.) - definition of Groups 3 and 4 in comparison to Tab. 5 Group 3 changes in % 4 changes in % Parameter male female male female platelet count − +47**⁾ +80 +54**⁾ Reticulocyte − − +64 +36**⁾ count Leukocyte count − − − −34

[0161] The external examination prior to the necroscopic examination showed a significant to heavy enlargement of the abdomen in all groups, with the exception of the control group, in which the abdomen in all animals was only slightly enlarged. The results of the macroscopic post mortem examination is shown in Table 7 (Tab. 7). TAB. 7 Necroscopic result in the subacute toxicity test - definition of the Groups in comparison to Tab. 4 Group 1 2 3 4 White yellow fluid in + + + + abdominal cavity¹⁾ White deposit or layer upon none + + + the diaphragm or upon the abdominal organs Stomach fur inflammation none none none + Abdominal space filled with none none none + white pulp-like/oily approximately content 30 ml

[0162] In this two week test for determination of the dose amount, the amount without effect lie at <500 mg birch extract/kg body weight. Significant to strong enlargement of the abdomen was observed at 500 mg/kg body weight and higher. Significant reduction of body weight was observed in all treated groups, however only in the male animals. Coarse or inflamed fur was observed at 1000 mg/kg body weight and higher. Certain hematological and/or biochemical parameters were changed significantly at 1000 mg/kg body weight and higher. The necroscopic examination showed white deposits upon the diaphragm or the abdominal organs, which were partially accompanied by adhesions at 500 mg/kg body weight and higher. In all groups the abdominal cavity was filled with an oily/watery fluid, which could be traced back to the carrier sesame oil. At 2000 mg/kg body weight 8 of 10 animals died. The necroscopic examination showed: 1) stomach fur infection in 4 of the prematurely deceased animals; 2) in all animals the abdominal cavity was filled with pulp-like/oily content. For the subchronic toxicity test an amount of 60 to 540 mg/kg body weight was selected.

[0163] Dogs (Beagle), i.p.

[0164] A subacute toxicity was carried out over a period of two weeks with Beagles as dose-determining experiment, over 4 weeks as subchronic toxicity test. The birch cork extract (Batch No.: Bet. 009) was administered intra-peritoneal with sesame oil as the carrier. The results are summarized in Table 8 (Tab. 8). TAB. 8 Subacute toxicity test in dogs (Beagle), i.p. Dose amount: 1. MTD*⁾ time 50, 150, 250, 500 mg/kg body weight/day 2. Fixed dose time 100, 300 mg/kg body weight/day Animals: 8 Beagles 2 beagles per sex and group

[0165] The results are shown in Table 9 (Tab. 9). TAB. 9 Subacute toxicity test in dogs (beagles), i.p. No effect: <50 mg/kg body weight/day during the MTD time Lethal dose: 500 mg/kg body weight/day Toxic indication during the fixed dose time: (100, 300 mg/kg body weight/day) Reduced body weight Reduced food uptake Change in hematopoetic and biochemical parameters Heavy stomach fur inflammation in 3 of 8 animals*⁾ 

1. Continuous process for obtaining triterpenes from plants and/or their components, comprising the following steps: (a) continuously introducing plant parts and a solvent, in which solvent the triterpenes are not soluble or only slightly soluble, and washing the plant parts with said solvent at 20° C. to 70° C. in counter-current; (b) continuously extracting triterpenes with the solvent under increased pressure and elevated temperature in counter-current; (c) continuously cooling and depressurizing the triterpene containing solution, whereby triterpene crystallizes out of the solvent of step (b); (d) filtering the triterpene at room temperature; (e) washing the triterpene in a solvent.
 2. Process according to claim 1, thereby characterized, that the triterpene is obtained from birch bark, preferably from the white part of the birch bark (birch cork).
 3. Process according to one of claims 1 or 2, thereby characterized, that the triterpene is obtained at a purity of at least 80%, preferably 80%, in particular 90%, and particularly preferrably above 90%.
 4. Process according to one of claims 1 through 3, thereby characterized, that the main component of the extracted triterpene is betulin.
 5. Process according to one of claims 1 through 4, thereby characterized, that the content of betulin is at least 80% preferably 85%, in particular 90%, particularly preferably above 90%.
 6. Process according to one of claims 1 through 5, thereby characterized, that the same solvent is employed in steps (a), (b) and (e).
 7. Process according to one of claims 1 through 6, thereby characterized, that the solvent is selected from the group consisting of supercritical CO₂, a low boiling carbohydrate or a mixture which includes a low boiling carbohydrate.
 8. Process according to one of claims 1 through 7, thereby characterized, that the solvent is selected from the group consisting of n-pentane, n-hexane and n-heptane.
 9. Process according to one of claims 1 through 8, thereby characterized, that the solvent used for step (a) is the solvent which is collected following step (b).
 10. Process according to one of claims 1 through 9, thereby characterized, that the washing in step (a) occurs under a pressure of 1 to 300 bar, preferably 10 to 35 bar, particularly preferably 25 bar.
 11. Process according to one of claims 1 through 10, thereby characterized, that extraction in step (b) occurs at a temperature of 50 to 200° C., preferably 140 to 160° C., particularly preferably at about 150° C. and under a pressure of 1 to 300 bar, preferably 10 to 35 bar, particularly preferably about 25 bar.
 12. Process according to one of claims 1 through 11, thereby characterized, that the crystallization out in step (c) occurs as micro-crystallization with an average particle size of <40 μm, in particular from 2 to 32 μm.
 13. Emulsion wherein the aqueous and fatty phases are emulsified using a plant extract, wherein the plant extract is at least one triterpene and/or at least one derivate of a triterpene and the emulsion further contains at least one oil and/or fat and water, thereby characterized, that the triterpene and/or it derivative is a preservative, emulsifier and pharmaceutical active substance in the emulsion.
 14. Emulsion according to claim 13, thereby characterized, that the plant extract is an extract from the bark of birch, preferably from the white part of the birch bark (birch cork).
 15. Emulsion according to claim 13 or 14, thereby characterized, that the plant extract is at least one substance selected from the group consisting of betulin, betulinic acid, lupeol, erythrodiol, allobetulin, phellonic acid, hydroxy-lactone, betulin aldyhyde, β-amyrin, oleanolic acid, ursolic acid, esterified betulin and/or β-sitosteol.
 16. Emulsion according to one of claims 13 through 15, thereby characterized, that the proportion of triterpene and/or its derivative comprises 2 to 10% of the total weight of the emulsion.
 17. Emulsion according to claim 16, thereby characterized, that the proportion of triterpene and/or it derivative comprises 2 to 3.5% or 3.5 to 10% of the total weight of the emulsion.
 18. Emulsion according to one of claims 13 through 17, thereby characterized, that the oil is avocado oil and/or almond oil.
 19. Emulsion according to one of claims 13 through 18 thereby characterized, that the emulsion further includes at least one moisturizing agent and/or at least one thickening agent.
 20. Emulsion according to claim 19, thereby characterized, that the moisturizing agent is glycerin and/or urea, which is added in a concentration of 3 to 10%, preferably 5% of each, based upon the amount of the emulsion.
 21. Emulsion according to claim 19, thereby characterized, that the thickening agent is a polysaccharide, which is added in a concentration of 0.2 to 2%, preferably 0.5%, based upon the amount of water.
 22. Emulsion according to claim 21, thereby characterized, that the polysaccharide is agar agar or carrageenan.
 23. Emulsion according to one of claims 13 through 22, thereby characterized, that the emulsion includes 2 to 10% extract from the white part of the birch bark, 20 to 30% avocado oil, 10 to 20% almond oil and 40 to 68% water.
 24. Emulsion according to claim 23, thereby characterized, that the emulsion comprises 4% extract from the white part of the birch bark, 29.3% avocado oil, 14.7% almond oil and 52% water.
 25. Emulsion according to one of claims 13 through 22, thereby characterized, that the emulsion comprises 2 to 10% extract from the white part of the birch bark, 20 to 30% avocado oil, 10 to 20% almond oil, 5 to 10% moisturizing agent and 30 to 63% water.
 26. Emulsion according to claim 25, thereby characterized, that the emulsion comprises 4% extract from the white part of the birch bark, 29.3% avocado oil, 14.7% almond oil, 5% glycerin and/or 5% urea and from 42 to 47% water.
 27. Emulsion according to one of claims 13 through 26, thereby characterized, that the extract from the white part of the birch bark comprises at least 80% betulin, at most 10% betulinic acid, at most 3% lupeol and at most 4% oleanolic acid.
 28. Process for producing an emulsion according to one of claims 13 through 27, which comprises the steps: (a) dispersing the triterpene in an oil and/or fat; (b) emulsifying water; (c) homogenizing the emulsion to the desired consistency.
 29. Process according to claim 28, thereby characterized, that the dispersing and the homogenizing steps are carried out in a homogenizer mixer.
 30. Process according to claim 28 or 29, thereby characterized, that a moisturizing agent is added to the water in step (b), in particular glycerin and/or urea, or a thickening agent, in particular a polysaccharide.
 31. Use of the triterpene for manufacture of a cosmetic, preferably in the form of a salve, a lotion, a cream, a gel, a jelly, a tincture, a shampoo, a powder and/or a compact powder, in particular for application to the skin, the face or scalp and/or for inhalation.
 32. Use of a triterpene for manufacture of a medicament, preferably in the form of a salve, a lotion, a cream, a gel, a jelly, a tincture, a shampoo, a powder and/or a compact powder, in particular for application to the skin, the face or scalp and/or for inhalation, particularly preferably for dermatological conditions of the skin and/or the scalp, above all for neuodermitis, psoriasis, seborrheic eczema, melanoderma, pre-cancerous conditions of the skin as well as inhalation in asthmatic attacks and/or for substitution in place of glucocorticoids. 